It is well known that wayside friction management application systems, including gage face (GF) lubrication systems and top of rail (TOR) friction modifier application systems are used to impart a number of benefits in railroad operations including reductions in lateral (track spreading) loads or curving forces, derailment probability, rail and wheel wear, energy (fuel) consumption, initiation and propagation of rolling contact fatigue, noise and corrugations.
Top of Rail friction modifier application systems, specifically, impart benefits in the areas listed above through control of friction at the TOR/wheel tread interface. TOR friction modifier materials, commonly used for this purpose, are water based liquids that establish a dry thin film at the wheel/rail interface once the water has been ejected.
Due to the nature of the materials of used in TOR friction control, direct detection of their presence at the wheel/rail interface can be difficult. Measurement and analysis of Lateral and Vertical forces in curves, and the ratio between the two (L/V) represents one of the most direct and immediate means to verify TOR friction control effectiveness. In practical settings, however, there are a substantial number of factors in addition to TOR friction control that can lead to a change in lateral/vertical forces at a given location, including changes in wheel/rail profiles (for example due to maintenance grinding or reprofiling operations), changes in the state of gage face lubrication, as well as intentional changes in the state of gage face and/or TOR lubricator states for the provision of maintenance activities. Due to changes in track conditions in areas that are subjected to increased wear and lateral forces, for example curves or regions with changes in elevation, control of a given wayside friction control application system based on one-off local measurements is insufficient for fully effective management of friction over a given territory.
U.S. Pat. No. 6,446,754 teaches the application of a lubricant to a track within a rail yard. The determination as to whether or not lubricant is to be applied is based on the speed of a rail car within the rail yard. U.S. Pat. No. 6,991,065 describes the application of lubricant to a track based on data received from vibration, sound or L/V sensors located at a target section of track. The determination as to whether lubricant is to applied to the track is made while the train passes though the target section of track.